With SRDF, you have the production volume (R1) which is being replicated to
the remote volume (R2 or cold standby). This replication is being done at
the physical hardware level via SRDF running on the array. Your host OS on
the remote side is unaware of these SRDF generated updates that are
happening to the R2. So, if you tried to mount that volume to AIX on the
remote location, while it is being updated by SRDF, this would be a BAD
thing. The data on the drive would be updated and the OS would not be aware
if it. Things could be added, deleted or changed while the host OS thinks
it has a very different view of the data.

So, EMC has set the R2 to a Sync'ed state. It is physically possible to
read from it, but there can be no local writes to that volume. AIX needs to
write to a volume if it is to mount it. This is not possible with the R2 in
Sync'ed mode.

So you can break off a point-in-time copy of this volume, but cannot access
it directly for any sort of updates.

mkbcv is nothing more than a script that executes the native aix /etc/methods/cfgscsidisk to change the bcv device from defined to available. Don't forget to use the -a option. I always did. The deal is ya gotta load the emc ODM definitions 'cause aix has no concept of a bcv. The ODM defs are on the emc ftp site as well as mkbcv and the emc_cfgmgr.sh. You wanna put this thing in a SAN? Verify you have the current EMC approved drivers first of all. That is posted on the powerlink. After that everything else is the same as any other host attach. Assign the symdevs to the FA, edit the zoneset, make the device masking assignments and run emc_cfgmgr.sh on it. Just don't ask me to do it is all.

Yeah BCV is a type of the device in the Symm.. I would get you can carve up raw disk space in to BCV if you want .. But i am not sure from Command .. may be mkbcv is the one way to do .. and other is with ECC..
Murthy

Hi,
You can create BCV devices from the command line, using the EMC
CLI symconfigure (with the create keyword). However if you're not
already familiar with this command it may be easier and safer to create
the devices from within ECC.
Either way, you'll need to know cylinder count and emulation
that you want to give the devices, you can get this from a symdev -sid
SYMMETRIXID show DEV of the device that you want to associate the BCV's
to. You'll need to feed this information, as well as the number of BCV's
you want, into the device creation dialog.

Hi,
Think that you'll need to get your San team to create the BCV's
and allocate them to the server on which you would like to use them.
Once you have that sorted out, you'll need to work with them to create a
device group and associate BCV's so that you can split, join and
generally make use of your BCV's.

Data isn't copied at the point of BCV creation, but at the point that
the BCV is established with the source disk, then all tracks will be
copied from the source to the BCV. Time taken will depend on size of
volume and how busy your Symm is. Subsequently when BCV's are split and
then re-established only updated tracks will need to be copied, cutting
down the length of time taken.

Suggest you have a look at the white papers on powerlink for a more
comprehensive explanation of the process.